Ever walked into a carpark and seen a car very similar to yours? Same make and model? Same REGISTRATION NUMBER??
This is exactly what has happened to Abu Dhabi blogger, Oriental Arabesque (a friend of a friend, Samer Al Ramahi in Amman*.)
The only difference in the registration plates is the background colour of the centre section. (Software developers reading this will have fallen off their chairs at the opening paragraph. Graphic designers will be gasping for air about now. And speedsters will be thinking, Wouldn’t it be sweet if my speed camera fines went to someone else?)
Duplicate Primary Keys, anyone?
This is reminiscent of my experience leading a team which developed a system for my state’s Transport Department. The system was to track taxi vouchers. These vouchers were issued by the Health Dept to old and infirm people who were not disabled enough to need an ambulance but were unable to catch public transport to medical appointments. Patients used the vouchers to pay for their taxi trips to hospital and drivers then submitted the vouchers to the Transport Dept for reimbursement.
Of course, each voucher was identified by a unique serial number. One part of our system recorded the voucher number against the patient name as they were issued. Another part recorded the voucher number against the taxi driver as they were submitted for reimbursement.
Everything went swimmingly for a few years. At any time we could tell how many vouchers were in circulation and how old they were. With our unique voucher number as a primary key, we could detect data entry errors and fraud attempts. Life was sweet, until…
One day, they ran out of vouchers. No problemo. We’ll just print some more, they said. Now, what number should we start at when printing the new vouchers? I know! Let’s start at 1!
We had to mangle our system to allow data entry of duplicate voucher numbers, but only 2 duplicates, and no more. Data entry performance took a major hit, and we looked like the culprits. Aaargh!
Technical papers from nutcases make the best reading
At about this time, I was also helping organise an international conference. All these erudite technical papers come in from practitioners and academics. These have to be reviewed, accepted and printed in the conference proceedings. 1% of these will be from pranksters who are just pulling your leg. It’s important to spot these and weed them out. Another 1% will be from genuine fruitcakes and these papers are the real gems.
One such fruitcake wanted to alert the world that it was dangerous to get your photo taken for your driver’s licence. “The Government” was doing more than just taking your photo. Yes, ladies and gentlemen, “The Government” was implanting a number IN YOUR BRAIN, right behind your forehead. And this number was 666, the Mark of the Beast.
Now, implicit in the above assertion, was the fact that everyone got the same number. Our programmer, Robert MacGregor (Where are you these days, Rob?) who did the hard yards on the aforementioned duplicate taxi voucher data entry programs, said “Pfft! Transport Department! That’d be right. Everybody gets the same Primary Key!“
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Afterthought: I wonder if the guy who was responsible for printing the duplicate taxi vouchers was banished to Abu Dhabi where he is now working in the Transport Department.
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* Go on, pay Samer a visit. He has recently become engaged and now shares his blog with his fiancee, “Mrs. Al Ramahi”. It’s always encouraging to know that people on the other side of the planet from different cultures have the same hopes and dreams that we do.